Significant efforts have been invested in developing aqueous quenching media. Such aqueous quenching media, or quenchant media, comprise water compatible polymers, for example starch, alkylene oxide polymers or polyacrylates.
Such quenching media are disclosed for example in U.S. Pat. Nos. 6,689,227, 4,381,205 and 5,766,505.
U.S. Pat. Nos. 3,939,016 and 3,996,076 teach the use of a aqueous quenching medium that comprises polyacrylic acid, polymethacrylic acid, a copolymer of acrylic acid and methacrylic acid or a salt thereof.
Surprisingly, it has been found that certain hydrophobically modified polyacrylate copolymers provide for an excellent aqueous metal quenching medium.